1. Field of the Invention
The present disclosure relates generally to shock absorbers having secondary dampening assemblies. Specifically, the present disclosure describes secondary dampening assemblies having a secondary compression valve assembly for secondary dampening.
2. Description of the Related Art
Conventional shock absorber assemblies known in the related art typically include an outer tube, a piston assembly, a rod, fluid, and one or more valves, whereby the piston assembly is connected to the rod and travels within fluid in the outer tube in operation so as to dampen axial movement of the rod with respect to the outer tube. To that end, respective opposing ends of the rod and outer tube are attached to different members or structures so as to dampen movement therebetween. By way of example, conventional automotive suspension systems utilize shock absorbers in connection with springs external to the shock absorber assembly to control the suspension dampening in compression and rebound, whereby the shock absorber assembly is typically attached to a knuckle supporting a wheel at one end, and to a portion of the vehicle's frame or body at the other end.
Depending on the application, the shock absorber assembly may also include an inner tube disposed inside the outer tube, wherein the piston assembly is instead supported in the inner tube. The shock absorber assembly is sealed at an end that receives the piston assembly. The inner tube defines a working chamber filled with fluid through which the piston assembly can move in operation. The piston assembly generally divides the working chamber into an upper working chamber and a lower working chamber. Similarly, a reservoir chamber is defined in the space between the outer tube and the inner tube. The reservoir chamber also contains fluid and is in regulated fluid communication with the working chamber via one or more valves. The chambers are sealed to prevent the leakage of fluid therefrom. The outer tube typically engages a rod guide assembly to seal the chambers.
During normal shock absorber assembly operation, the shock absorber assembly is extended and compressed during vehicle wheel and body articulation. During compression, the shock absorber assembly builds force and provides a single dampening force curve. If the shock absorber assembly is completely compressed during wheel or body articulation, a condition referred to as “bottoming out” occurs and causes an abrupt metal-to-metal noise. Further, the condition causes harsh feedback and/or vibrations that are felt by the driver.